The invention relates to an apparatus for processing yarn packages for dyeing and, in particular, to an apparatus for replacing a relatively impervious transfer core of a yarn package with a dye penetrating foraminous core.
Yarn that has been processed for dyeing may be in the form of bulked continuous filament thermoplastic yarn such as polyester, nylon or cellulose triacetate yarn, as well as spun yarn, such as direct spun rayon having residual shrinkage of up to 20 percent when exposed to conditions of high humidity or when immersed in aqueous solutions, or acrylic yarn having high residual shrinkage by reason of unrelaxed heat sensitive fibers in the yarn. This yarn is generally wound into package form about a cardboard or paper transfer core or tube such that the outer portion of the package is at substantially a desired bulk level whereas the innner portion is somewhat below this level. As disclosed in U.S. Pat. No. 3,425,110, the bulk level of the inner portion of the package may be increased by simultaneously removing the cardboard package core while inserting a perforate dye core or tube of a predetermined smaller diameter than the cardboard core. The inner portion of the highly stretchable yarn then contracts (and gains bulk) about the perforate core.
Apparatus for replacing the cardboard core with a perforate core is disclosed in the aforesaid patent. However, such apparatus is subject to various drawbacks. The apparatus employs a vertically movable mandrel upon which is placed a perforate core. Upon actuation, the perforate core is pushed downwardly into engagement with a cardboard core in the yarn package, whereupon the continued downward movement causes the perforate core to push the cardboard core completely out of the package. Owing to the pressure and movement of the entering perforated core, there is a tendency of the yarn package to come apart and unduly distort. The apparatus is only able to process yarn packages singly whereas multiple package processing is more desirable for economy and efficiency purposes. Further, owing to the fact that both the cardboard transfer core and perforated dye core simultaneously move through the yarn it has been found necessary to sandwich a paper or knit sleeve or sock between the yarn and the transfer core to serve as a bridge or shield during transfer. Without the sleeve it has been observed that some of the strands of yarn become trapped between the ends of the transfer core and the dye core during the operation, thereby disturbing the continuity of the yarn.
As set forth in the above-referenced application Ser. No. 105,920, it has been found that the above drawbacks and disadvantages are overcome by placing a replacement dye core within the cardboard transfer core and thereafter pulling the cardboard core out of the yarn package to permit the package to contract around the replacement core. Apparatus for performing such a process has been proposed as set forth in the co-pending application. While achieving satisfactory results, further improvements have now been provided for simultaneously processing at least two yarn packages in continuous operation. Provision is also made for effective handling and disposing of the cardboard transfer core.